If you are just noticing your parents age catching up with them, they are probably happy at home.  In fact, with some outside resources and some home modifications, they may be able to stay at home for most, if not all, of their lives.

A few items to keep in mind are the community around your parents.  How close do you live to your parents.  If you cannot get to your parents quickly, can a close friend or long-time neighbor help out?

As soon as we see our parents start to decline we want to move them somewhere with additional care.  I know I have had the fear (and the reality) of my mom or dad falling at home and not getting any help.  But really, is this your fear or your parents' fear?  Plus there are alternatives like medic-alert and other services that will help your parents.  The proliferation of cell phones can also help by making your parents more accessible.  There is even a cell phone service specifically for seniors, the Jitterbug.

Regardless of what decisions lie ahead, a conversation with your parents is the place to start.  No one wants to be moved from their home into a new location because they are getting older.  So to start this conversation by telling your parents about assisted livign options will probably not result in the desired result.  In fact, it might stop any further conversations.  Start with reviewing how your parents are managing.  For example, if they can drive less and less, are they still able to handle basic tasks such as getting groceries (perhaps via a delivery services) and doctor's appointments (most hospitals provide neighborhood pickup and drop off service).  What about other, non-essential, services?  For example, hair appointments?  While most hospitals provide pickup and drop off, I do not know of many hair salons that offer this service!